Transcription profiling of primary lung cells to identify targets of the novel Rho GTPase RhoBTB2
Ontology highlight
ABSTRACT: RhoBTB2 is a novel Rho GTPase that undergoes loss, underexpression and mutation in breast and lung cancer. We have shown that we can mimic loss of RhoBTB2 through siRNA treatment of primary cells. We propose to perform comparative microarray analysis of primary lung cells to establish the identification of the gene targets of RhoBTb2 regulation. Experiment Overall Design: Primary lung cells (NHBE) transfected with siRNA oligonucleotides against cyclophilin or Lamin A/C (controls) were compared to cells transfected with siRNA oligonucleotides against RhoBTB2. We used two siRNA oligonucleotides against RhoBTB2 (1 and 2) to determine any non-specific effects. Cells expressed the siRNA oligonucleotides for 72 hours before total RNA extraction. 10 samples have been analysed.
Project description:RhoBTB2 is a novel Rho GTPase that undergoes loss, underexpression and mutation in breast and lung cancer. We have shown that we can mimic loss of RhoBTB2 through siRNA treatment of primary cells. We propose to perform comparative microarray analysis of primary lung cells to establish the identification of the gene targets of RhoBTb2 regulation. Experiment Overall Design: Primary lung cells (NHBE) transfected with siRNA oligonucleotides against cyclophilin or Lamin A/C (controls) were compared to cells transfected with siRNA oligonucleotides against RhoBTB2. We used two siRNA oligonucleotides against RhoBTB2 (1 and 2) to determine any non-specific effects. Cells expressed the siRNA oligonucleotides for 72 hours before total RNA extraction. 10 samples have been analysed.
Project description:RhoBTB2 is a novel Rho GTPase that undergoes loss, underexpression and mutation in breast and lung cancer. We have shown that we can mimic loss of RhoBTB2 through siRNA treatment of primary cells. We propose to perform comparative microarray analysis of primary lung cells to establish the identification of the gene targets of RhoBTb2 regulation. Keywords: Effects of siRNA expression
Project description:Myeloid cells are critical for innate immunity and the initiation of adaptive immunity. Strict regulation of the adhesive and migratory behavior is essential for proper functioning of these cells. Rho GTPases are important regulators of adhesion and migration; however, it is unknown which Rho GTPases are expressed in different myeloid cells. Here, we use a qPCR-based approach to investigate Rho GTPase expression in myeloid cells.We found that the mRNAs encoding Cdc42, RhoQ, Rac1, Rac2, RhoA and RhoC are the most abundant. In addition, RhoG, RhoB, RhoF and RhoV are expressed at low levels or only in specific cell types. More differentiated cells along the monocyte-lineage display lower levels of Cdc42 and RhoV, while RhoC mRNA is more abundant. In addition, the Rho GTPase expression profile changes during dendritic cell maturation with Rac1 being upregulated and Rac2 downregulated. Finally, GM-CSF stimulation, during macrophage and osteoclast differentiation, leads to high expression of Rac2, while M-CSF induces high levels of RhoA, showing that these cytokines induce a distinct pattern. Our data uncover cell type specific modulation of the Rho GTPase expression profile in hematopoietic stem cells and in more differentiated cells of the myeloid lineage.
Project description:Tissue fibrosis occurs with excessive extracellular matrix deposition from myofibroblasts, resulting in tissue scarring and inflammation. It is driven by multiple mediators, such as the G protein-coupled receptor ligands lysophosphatidic acid and endothelin, as well as signaling by transforming growth factor-β, connective tissue growth factor, and integrins. Fibrosis contributes to 45% of deaths in the developed world. As current therapeutic options for tissue fibrosis are limited and organ transplantation is the only effective treatment for end-stage disease, there is an imminent need for efficacious antifibrotic therapies. This review discusses the various molecular pathways involved in fibrosis. It highlights the Rho GTPase signaling pathway and its downstream gene transcription output through myocardin-related transcription factor and serum response factor as a convergence point for targeting this complex set of diseases.
Project description:The human nm23-H1 was discovered as a tumor metastasis suppressor based on its reduced expression in melanoma cell lines with low versus high metastatic potential. It encodes for one of two subunits of the nucleoside-diphosphate kinase. Besides its role in the maintenance of the cells NTP pool, nm23 plays a key role in different cellular processes. The role of nm23-H1 in these processes still has to be elucidated. Our goal was to identify Nm23-H1 downstream targets by subjecting Nm23-H1 overexpressing CAL 27 cells oral squamous cell carcinoma (OSSC) to microarray analysis. The genes with changed expression patterns could be clustered into several groups: transforming growth factor (TGF) signaling pathway, cell adhesion, invasion and motility, proteasome machinery, cell-cycle, epithelial structural and related molecules and others. Based on the expression patterns observed we presume that nm23-H1 might have a role in OSSCs, which should be confirmed by future experiments. Experiment Overall Design: The experiments were conducted on human cell line CAL 27 (poorly differentiated, G3, squamous cell carcinoma of the tongue), obtained by courtesy of Dr. Jeannine Gioanni, Centre Antoine Lacassagne, Nice France). The cells were transfected with pEGFPC1 and pEGFPC1-nm23-H1 constructs, and total cellular RNA was extracted from clones expressing EGFP-Nm23-H1 and the empty vector-carrying clone for microarray analysis.
Project description:The Mycobacterium tuberculosis protein kinase K regulates growth adaptation by facilitating mycobacterial survival in response to a variety of in vitro and in vivo stress conditions. Here, we further add that pknK transcription is responsive to carbon and nitrogen starvation signals. The increased survival of an M. tuberculosis ΔpknK mutant strain under carbon- and nitrogen-limiting growth conditions compared to the wild-type (WT) H37Rv suggests an integral role of PknK in regulating growth during metabolic stress. To identify the downstream targets of PknK-mediated signaling, we compared phosphoproteomic and transcription profiles of mycobacterial strains overexpressing WT and phosphorylation-defective PknK. Results implicate PknK as a signaling protein that can regulate several enzymes involved in central metabolism, transcription regulation, and signal transduction. A key finding of this study was the identification of two essential two-component response regulator (RR) proteins, PrrA and MtrA, and Rho transcription terminator, as unique targets for PknK. We confirm that PknK interacts with and phosphorylates PrrA, MtrA, and Rho in vivo. PknK-mediated phosphorylation of MtrA appears to increase binding of the RR to the cognate probe DNA. However, dual phosphorylation of MtrA and PrrA response regulators by PknK and their respective cognate sensor kinases in vitro showed nominal additive effect on the mobility of the protein-DNA complex, suggesting the presence of a potential fine-tuning of the signal transduction pathway which might respond to multiple cues. IMPORTANCE Networks of gene regulation and signaling cascades are fundamental to the pathogenesis of Mycobacterium tuberculosis in adapting to the continuously changing intracellular environment in the host. M. tuberculosis protein kinase K is a transcription regulator that responds to diverse environmental signals and facilitates stress-induced growth adaptation in culture and during infection. This study identifies multiple signaling interactions of PknK and provides evidence that PknK can change the transcriptional landscape during growth transitions by connecting distinctly different signal transduction and regulatory pathways essential for mycobacterial survival.
Project description:Gene expression profile of squamous lung cancer cells are used to identify genes that are differentially regulated. Experiment Overall Design: Each pair of samples represent a single patient with squamous lung cancer. One is derived from the cancer cells, and the other is from the normal cells. Five patients, with two arrays for each patients.
Project description:Background: Targeted therapy for lung cancer with epidermal growth factor receptor (EGFR) mutations with tyrosine kinase inhibitors (TKIs) represents one of the major breakthroughs in lung cancer management. However, gradually developed resistance to these drugs prevents sustained clinical benefits and calls for resistant mechanism research and identification of new therapeutic targets. Acquired T790M mutation accounts for the majority of resistance cases, yet transcriptome changes in these cells are less characterized, and it is not known if new treatment targets exist by available drugs. Methods: Transcriptome profiling was performed for lung cancer cell line PC9 and its resistant line PC9GR after long-term exposure to gefitinib through RNA sequencing. Differentially expressed genes and changed pathways were identified along with existing drugs targeting these upregulated genes. Using 144 lung cancer cell lines with both gene expression and drug response data from the cancer cell line encyclopedia (CCLE) and Cancer Therapeutics Response Portal (CTRP), we screened 549 drugs whose response was correlated with these upregulated genes in PC9GR cells, and top drugs were evaluated for their response in both PC9 and PC9GR cells. Results: In addition to the acquired T790M mutation, the resistant PC9GR cells had very different transcription programs from the sensitive PC9 cells. Multiple pathways were changed with the top ones including TNFA signaling, androgen/estrogen response, P53 pathway, MTORC1 signaling, hypoxia, and epithelial mesenchymal transition. Thirty-two upregulated genes had available drugs that can potentially be effective in treating the resistant cells. From the response profiles of CCLE, we found 17 drugs whose responses were associated with at least four of these upregulated genes. Among the four drugs evaluated (dasatinib, KPT-185, trametinib, and pluripotin), all except trametinib demonstrated strong inhibitory effects on the resistant PC9GR cells, among which KPT185 was the most potent. KPT-185 suppressed growth, caused apoptosis, and inhibited migration of the PC9GR cells at similar (or better) rates as the sensitive PC9 cells in a dose-dependent manner. Conclusions: Acquired TKI-resistant lung cancer cells (PC9GR) have dramatically changed transcription and pathway regulation, which expose new treatment targets. Existing drugs may be repurposed to treat those patients with developed resistance to TKIs.
Project description:Immunoconjugates targeting cell-surface antigens have demonstrated clinical activity to enable regulatory approval in several solid and hematologic malignancies. We hypothesize that a rigorous and comprehensive surfaceome profiling approach to identify osteosarcoma-specific cell-surface antigens can similarly enable development of effective therapeutics in this disease. Herein, we describe an integrated proteomic and transcriptomic surfaceome profiling approach to identify cell-surface proteins that are highly expressed in osteosarcoma but minimally expressed on normal tissues. Using this approach, we identified targets that are highly expressed in osteosarcoma. Three targets, MT1-MMP, CD276, and MRC2, were validated as overexpressed in osteosarcoma. Furthermore, we tested BT1769, an MT1-MMP-targeted Bicycle toxin conjugate, in osteosarcoma patient-derived xenograft models. The results showed that BT1769 had encouraging antitumor activity, high affinity for its target, and a favorable pharmacokinetic profile. This confirms the hypothesis that our approach identifies novel targets with significant therapeutic potential in osteosarcoma.
Project description:"Gene transcription in a set of 49 human primary lung adenocarcinomas and 9 normal lung tissue samples was examined using Affymetrix GeneChip technology. We aimed to investigate differential gene expression between the two tissue types. A total of 3,442 genes, called the set MAD, were found to be either up- or down-regulated by at least two fold between the two phenotypes. Genes assigned to a particular gene ontology term were found, in many cases, to be significantly unevenly distributed between the genes in and outside MAD. Terms that were overrepresented in MAD included functions directly implicated in cancer cell metabolism. Based on their functional roles and expression profiles, genes in MAD were grouped into likely co-regulated gene sets."